New overpass set to open by the end of the year

At the start of the year, it wasn’t much more than a few dozen steel beams and some columns sticking out of the ground. As the calendar turns to July 2013, the new South Atlantic Street overpass is taking shape at the southern edge of the State Route 99 tunnel construction site near the stadiums.

The overpass will address a bottleneck near the entrance to the Port of Seattle’s Terminal 46, where trains crossing South Atlantic Street frequently block traffic. When it opens at the end of 2013, the overpass will enable traffic and freight to bypass train blockages, resulting in reduced congestion in the area.

If you’ve driven by the project site on SR 99 recently, you may have wondered why so much of the overpass seems to be made out of wood. The wood is falsework, the temporary structure that holds the permanent concrete and steel in place until it can stand on its own. The falsework will be removed this fall. The north end of the overpass, on the west side of SR 99, will initially be used as a haul road for crews building the tunnel. Later it will connect to the new Alaskan Way that will be built as part of the City of Seattle’s Waterfront Seattle project.